MOUFDI Hadjab

OUADAH Khadidja , BOUDRAI Souad

Etude des propriétés physiques du matériau Mg3ZnO4 par la méthode FP-LAPW

SOUIDI Nadjet , CHELLALI Nour Elhouda

Développement des performances des cellules solaires

HAMOUDI Ilham , KHEIRI Idriss

Modélisation du comportement optoélectronique de matériaux semi-conducteurs à partir de calculs de premiers principes.

DEKHANE Sara , DEMMANE Khaoula

Etude par simulation numérique des propriétés physiques des matériaux semiconducteurs pour application photovoltaïque

MADANI Hossem , SOLTANI Souhib

Etude comparative entre différentes structures de cellules solaires à hétérojonction

BENDIFF Mounir Mohamed , BADA Mohamed

Contribution à l’étude des propriétés physiques fondamentales des matériaux chalcopyrites pour des applications photovoltaïques

DILMI Youssouf , SEKHARA Farid

Etude des propriétés optoélectroniques des scintillateurs inorganiques pour des applications de sécurité nucléide

Through experimental exploration, diverse phases—tetragonal and orthorhombic—have been observed within the Cu ZnGeSn2x1−xS4 region (0 ≤ x ≤ 1), hinting at potential miscibility gaps. To complement these findings, our computational investigation, employing density functional theory (DFT), delves into the Ge substitution-induced phase transition in Cu2ZnGeSnx1−xS4. Contrary to a single-phase behavior, our FP-LAPW at zero temperature results reveal a compelling shift from stannite (Sn-rich) to Wurtzite-Stannite (Ge-rich) at xGe ≈ 80%. Negative enthalpy of formation values indicates the inherent stability of these structures. The calculations reveal an estimated 8.884 meV per atom difference in enthalpies of formation between the Stannite and Wurtzite-Stannite phases for Cu2ZnSnS4. For Cu2ZnGeS4, the Wurtzite-Stannite structure emerges as the most stable, closely trailed by the Stannite structure, with enthalpies of formation at − 4.833 eV⋅atom− 1 and − 4.804 eV⋅atom− 1, respec- tively. Furthermore, our quasi-harmonic Debye model facilitates the analysis of phase transitions triggered by the introduction of germanium. This is achieved by calculating the Gibbs energy, which remains unaffected by variations in temperature and pressure. As the tin cation is replaced by the smaller germanium cation, there is an observable decrease in the cell parameters. The corresponding reduction in cell volume adheres to the principles of Vegard’s Law. Exploring the behavior of these materials in diverse conditions can significantly contribute to enhancing the performance and stability of devices built upon Cu2ZnGe Sn x 1− xS4.

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Moufdi Hadjab , Hamza BENNACER , Ziane Mohamed Issam, , (2023-12-25), Investigating solid solutions: Geometric transformations triggered by germanium incorporation in Cu2ZnGeSnx1−xS4, Materials Today Communications, Vol:38, Issue:1, pages:9, Elsevier

This study focuses on investigating the phase transitions in two materials, Cu 2 ZnSnS 4 (CZTS) and Cu 2 ZnGeS 4 (CZGS), which are important for understanding their structural and functional properties. The temperature and pressure-induced tetragonal-orthorhombic phase transitions in these materials are analyzed using density functional theory (DFT) and the quasi-harmonic Debye model. The research aims to examine the changes in the material's structure and the associated thermodynamic properties during these phase transitions. The results reveal that both compounds exhibit a negative value of δH mix , indicating the release of energy during the mixing process, which suggests an exothermic nature. The DFT calculations at zero temperature and pressure demonstrate that the stannite structure represents the ground state configuration of the Cu 2 ZnSnS 4 system (with x Ge = 0%), compared to the wurtzite-stannite structure. The calculations also show that the difference in enthalpies of formation (δH) between the stannite and wurtzite-stannite phases for CZTS is estimated to be 8.884 meV per atom. Regarding Cu 2 ZnGeS 4 , the wurtzite-stannite structure is found to be the most stable, closely followed by the stannite structure, with enthalpies of formation of −4.833 eV·atom −1 and −4.804 eV·atom −1 , respectively. Notably, there are no definitive reports on enthalpy studies for the Cu 2 ZnGeS 4 system in the existing literature. Understanding the behavior of these materials under different conditions can contribute to the development of improved performance and stability of devices based on CZTS and CZGS.

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Hamza BENNACER , Moufdi Hadjab , , (2023-12-19), Temperature and Pressure-Induced Phase Transitions in Cu2ZnSnS4 and Cu2ZnGeS4: Thermodynamic Analysis and Structural Transformations, Engineering Proceedings, Vol:56, Issue:, pages:Eng. Proc. 2023, 56(1), 127, MDPI

In this work, we investigated the optoelectronic properties of MgZnO using density functional theory based on linear augmented plane wave (FP-LAPW) method. To deal with the exchange-correlation potential for total energy calculations, the LDA and GGA approximations were used. In addition, the modified Becke Johnson (TB-mBJ) approach, which successfully corrects the band gap problem, was used for the band structure calculations. The calculated lattice constants and band gap values for this compound are in good agreement with available theoretical data. As well as the dielectric function and the absorption coefficient are calculated to get the optical parameters. The achieved results indicate that this material is particularly interesting for photovoltaic conversion applications.

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Hamza BENNACER , Moufdi Hadjab , ,(2023-10-31), First-principles study on optoelectronic properties for caswellsilverite mixed metal oxide MgZnO,The 4th International Electronic Conference on Applied Sciences (ASEC2023),Online

This study focuses on investigating the phase transitions in two materials, Cu 2 ZnSnS 4 (CZTS) and Cu 2 ZnGeS 4 (CZGS), which are important for understanding their structural and functional properties. The temperature and pressure-induced tetragonal-orthorhombic phase transitions in these materials are analyzed using density functional theory (DFT) and the quasi-harmonic Debye model. The research aims to examine the changes in the material's structure and the associated thermodynamic properties during these phase transitions. The results reveal that both compounds exhibit a negative value of δH mix , indicating the release of energy during the mixing process, which suggests an exothermic nature. The DFT calculations at zero temperature and pressure demonstrate that the stannite structure represents the ground state configuration of the Cu 2 ZnSnS 4 system (with x Ge = 0%), compared to the wurtzite-stannite structure. The calculations also show that the difference in enthalpies of formation (δH) between the stannite and wurtzite-stannite phases for CZTS is estimated to be 8.884 meV per atom. Regarding Cu 2 ZnGeS 4 , the wurtzite-stannite structure is found to be the most stable, closely followed by the stannite structure, with enthalpies of formation of −4.833 eV·atom −1 and −4.804 eV·atom −1 , respectively. Notably, there are no definitive reports on enthalpy studies for the Cu 2 ZnGeS 4 system in the existing literature. Understanding the behavior of these materials under different conditions can contribute to the development of improved performance and stability of devices based on CZTS and CZGS.

Citation

Hamza BENNACER , Moufdi Hadjab , ,(2023-10-27), Temperature and Pressure-Induced Phase Transitions in Cu2ZnSnS4and Cu2ZnGeS4 : Thermodynamic Analysis and Structural Transformations,The 4th International Electronic Conference on Applied Sciences (ASEC2023),Online

In this work, we investigated the optoelectronic properties of MgZnO using density functional theory based on linear augmented plane wave (FP-LAPW) method. To deal with the exchange-correlation potential for total energy calculations, the LDA and GGA approximations were used. In addition, the modified Becke Johnson (TB-mBJ) approach, which successfully corrects the band gap problem, was used for the band structure calculations. The calculated lattice constants and band gap values for this compound are in good agreement with available theoretical data. As well as the dielectric function and the absorption coefficient are calculated to get the optical parameters. The achieved results indicate that this material is particularly interesting for photovoltaic conversion applications.

Citation

Moufdi Hadjab , ,(2023-10-27), First-principles study on optoelectronic properties for caswellsilverite mixed metal oxide MgZnO,The 4th International Electronic Conference on Applied Sciences,On line

In this study, we investigate the structural changes, electronic properties, and charge redistribution within azo-bithiophene (Azo-BT)-chemisorbed monolayers under different light stimuli using the density functional theory and molecular dynamics simulations. We consider two types of switches, Azo-BT and BT-Azo, with different arrangements of the Azo and BT blocks counting from the anchor thiol group. The chemisorbed monolayers of pure cis- and trans-isomers with a surface concentration of approximately 2.7 molecules per nm are modeled on a gold surface using the classical all-atom molecular dynamics. Our results reveal a significant shrinkage of the BT-Azo layer under UV illumination, whereas the thicknesses of the Azo-BT layer remain comparable for both isomers. This difference in behavior is attributed to the ordering of the trans-molecules in the layers, which is more pronounced for Azo-BT, leading to a narrow distribution of the inclination angle to the gold surface. Conversely, both layers consisting of cis-switches exhibit disorder, resulting in similar brush heights. To study charge transfer within the immobilized layers, we analyze each snapshot of the layer and calculate the mean charge transfer integrals using Nelsen’s algorithm for a number of interacting neighboring molecules. Combining these integrals with reorganization energies defined for the isolated molecules, we evaluate the charge transfer rates and mobilities for electron and hole hopping within the layers at room temperature based on Marcus’ theory. This research offers new perspectives for the innovative design of electrode surface modifications and provides insights into controlling charge transfer within immobilized layers using light triggers. Additionally, we identify molecular properties that are enhanced via specific molecular design, which contributes to the development of more efficient molecular switches for various electronic applications.

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Moufdi Hadjab , Vladyslav Savchenko, Alexander S. Pavlov, Olga Guskova, , (2023-09-05), Photo-Programmable Processes in Bithiophene–Azobenzene Monolayers on Gold Probed via Simulations, Processes, Vol:11, Issue:1, pages:17, MDPI

Transparent conducting oxides (TCO) possessing high optical transparency and electrical conductivity have been studied widely due to their applications in optoelectronics. Delafossite materials with chemical formula AIBIIIO2 are among the promising p-type TCOs. In this study, we have investigated physical properties of three novel semiconductors to address some problems related to the photovoltaic industry. The structural, electronic and optical properties of delafossite transparent conducting oxides CuMO2 have been studied using the Full-Potential Linearized Augmented Plan Wave method based on DFT as implemented in Wien2k computational code. The LDA and PBE generalized gradient approximation have been utilized as the exchange–correlation term for calculating the structural and electronic parameters. Moreover, Tran-Blaha modified Beck–Johnson potential has been used to achieve better degree of accuracy in calculations of the electronic and optical properties. The observations have been compared with published theoretical and experimental data. The ternary delafossite transparent conducting oxide compounds can be considered as an alternative material in photovoltaic applications.

Citation

Moufdi Hadjab , ,(2023-03-26), Electronic and optical properties of p-type delafossite transparent conducting oxides: Density Functional Theory calculations,DPG Spring Meeting (SKM23),Dresden - Germany

We investigate the initial stages of the adsorption and thin-film formation of N-unsubstituted difuryl - diketopyrrolopyrroles (Figure 1) on graphite. The cis-cis, cis-trans or trans-trans Fu-DPP-Fu conformers build the adsorption layers during in-silico self-assembly on graphite through intermolecular hydrogen bonding. Here, both vacuum deposition (VD) of the molecules and droplet deposition techniques (DD) are reproduced in the all-atom MD setup. We compare the properties of the layers prepared by two approaches and quantify the energetics of intermolecular interactions and the interactions with graphite.

Citation

Moufdi Hadjab , ,(2023-03-26), Diketopyrrolopyrroles on graphite: Carpets self-assembled via hydrogen bonding,DPG Spring Meeting (SKM23),Dresden - Germany

The electronic band gap energy is an essential photo-electronic parameter in the energy applications of engi- neering materials, particularly in solar cells and photo-catalysis domains. A prediction model that can correctly predict this band gap energy is desirable. A new approach for predicting a band gap energy is suggested in this paper. The proposed structure is based on artificial neural networks (ANN) and the particle swarm optimization algorithm (PSO); this structure can solve the artificial neural network’s local minima issue while preserving the fitting quality. Our technique will hasten the identification of novel chalcopyrite in photovoltaic solar cells with improved resolution. The suggested model combines two sub-systems in a parallel configuration. A conventional prediction system with a low resolution for the training data being considered makes up the first ANN sub- system. A second ANN sub-system, labelled the error model, is introduced to the primary system to address the resolution quality issue, representing uncertainty in the primary model. The particle swarm optimization algorithm is used to identify the parameters of the proposed neural system. The method’s effectiveness is assessed in terms of several criteria, and the output of our system shows good performance compared to experimental and other calculated results. Several benchmark approaches were compared with the proposed system in detail. Numerous computer tests show that the suggested strategy can significantly enhance convergence and resolution.

Citation

Moufdi Hadjab , , (2023-01-02), A new ANN-PSO framework to chalcopyrite’s energy band gaps prediction, Materials Today Communications, Vol:34, Issue:1, pages:11, Elsevier

Nanostructure based perovskite solar cells with high performance are the focus of study in current work, keeping in view the improvement in cell efficiency. In the rst part of the study, a plane-layered solar cell is studied by adding a 1D Photonic Crystal (1D PhC) at the bottom of the cell in order to facilitate the photon rotation process. However, in the second part of the study, it is observed that the addition of grating enhances the light absorption due to photon trapping. Following that, the light absorption of three different structures is compared. The observations reveal that the short-circuit current density (Jsc) is found to be 􀀀39:93mA/cm2, which is 87.29% higher than that for a planar structure exhibiting the short-circuit current density (Jsc) value of 􀀀21:32mA/cm2. Finally, the efficiencies of these nanostructured perovskite solar cells are found to be signicant. For the proposed solar cell structure an 87.24% improvement in the power conversion efficiency (PCE) is observed, i.e., from 14.03% for the planar structure to 26.27%.

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Maroua chahmi , Mounir BOURAS , Moufdi Hadjab , , (2022-12-11), Light Trapping for Absorption Control in Perovskite-Based Photovoltaic Solar Cells, Progress In Electromagnetics Research Letters, Vol:108, Issue:2023, pages:41{48, PIER

In this work, we propose a new photovoltaic cell based on the ternary compound CdSnP2 as absorber, the binary compound CdS as a buffer layer and ZnO as a window layer, (n-ZnO/n-CdS/p-CdSnP2). In this study, we investigate the effect of the thickness and the doping concentration of the absorber layer and the buffer layer on the performance of solar cells such as; the J-V and P-V characteristics, in particular; {photovoltaic conversion efficiency (η), fill factor (FF), open circuit voltage (Voc) and short-circuit current density (Jsc). In addition, the external quantum efficiency (EQE) for thin film structure was calculated by modelling and simulation of the n-ZnO/n-CdS/p-CdSnP2 solar cell, using the wxAMPS-1D one-dimensional simulation software.

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Moufdi Hadjab , ,(2022), Numerical study of ZnO/CdS/CdSnP2 solar cells,3rd International Conference on Applied Engineering and Natural Sciences (ICAENS’22),Konya-Turkey

In this work, we have used the “RSOFT’s Diffract MOD and solar Cell Utility” based on the Rigorous Coupled Wave Analysis (RCWA) technique to analyze the behavior of the perovskite-based solar cell. Here, the RSoft CAD (Photonic Device Tools) was utilized to determine the effect of materials in different layers of a perovskite-based solar cell on the power conversion efficiency (PCE) and other useful parameters, such as the density of the current-voltage (J-V) measurements. Therefore, we chose the perovskite as an active layer, PDMS as a window layer and gold (OR) as a reflective layer. Here, Different ETM and HTM candidates have been suggested. Firstable, HTM was proposed randomly and presented by P3HT and the ETM is presented by TiO2, ZnO and ZnS, and thus, it was found that the best ETM is ZnS because the enhanced PCE increased from 18.30% when we use the ZnSe to 21.19% when the ZnS is chosen. Secondly, the optimum ETM candidate was selected and presented by ZnS, and the two HTM candidates were changed and presented by P3HT and AZO. It was found that the best HTM is the AZO, and the PCE of this perovskite-based solar cell reached the value 21.43%.

Citation

Moufdi Hadjab , ,(2022), Optimization study of perovskite-based solar cells using R-soft package,3rd International Conference on Applied Engineering and Natural Sciences (ICAENS’22),Konya-Turkey

In this study, we have investigated physical ground-state properties of three novel semiconductors to address many problems related to the photovoltaic (PV) industry. A computational package (wien2k) based on Density Functional Theory (DFT) is used to study the optical, structural, as well as electronic properties of delafossite transparent conducting oxides CuMO2 (M= Al, Sc and Y). The Full-Potential Linearized Augmented Plan Wave method (FP-LAPW) which is based on DFT has also been employed in this study. To compute the structural and electronic parameters the Local Density Approximation (LDA), Perdew, Burke and Ernzerhof Generalized Gradient Approximation (PBE-GGA) have been utilized as the exchange-correlation term. Furthermore, Tran-Blaha modified Beck–Johnson potential (TB-mBJ) has been utilized to achieve better degree of accuracy in computing the electronic and optical characteristics. The results of the study have also been compared to the previous theoretical and experimental ones. The ternary delafossite transparent conducting oxide compounds can be considered as an alternative material in photovoltaic applications.

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Hamza BENNACER , Moufdi Hadjab , , (2022), Ground-state properties of p-type delafossite transparent conducting oxides 2H-CuMO2 (M=Al, Sc and Y): DFT calculations., Materials Today Communications – Elsevier., Vol:32, Issue:, pages:103995, Elsevier

Double perovskite oxides have received a lot of interest in the last ten years because of their distinctive and adaptable material properties. Among the six parameters in the cubic structure, the lattice constant is the sole changeable parameter, which plays an important role in developing materials for particular technological applications and distinctively identifies the crystal structure of the material. In this paper, the extreme learning machine (ELM) is used to correlate the lattice constant of A_2^(+2) BCO_6 cubic perovskite compounds, such as their ionic radii, electronegativity, oxidation state, and lattice constant. We investigated 147 compounds with lattice constants between 7.700 and 8.890Å. The prediction method has a high level of accuracy and stability and provides accurate estimates of lattice constants.

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Hamza BENNACER , MOHAMMED ASSAM Ouali , Mohamed Ladjal , Moufdi Hadjab , Inas bouzateur , ,(2022), Lattice Constant Prediction of Complex Cubic Peroveskite A2BCO6 using Extreme Learning Machine,International Conference of advanced Technology in Electronic and Electrical Engineering (ICATEEE),Msila, Algeria

This work utilizing “RSOFT’s Diffract MOD and solar Cell Utility” based on RCWA calculation to analyze the behavior of the solar cell and to compute the PCE (power conversion efficiency) (RSoft CAD photonic device tools) was used to study the effect of the materials used in the different layers of the perovskitebased solar cell on the efficiency of this cell. We used perovskite as the active layer, PDMS as a window layer, ZnS as ETL (electron transport layer) and AZO as HTL (hole transport layer). and make a change of reflective layer from Au (Gold) to different reflective layers candidate have been suggested. So that in the beginning we used gold as a reflective layer, we found the efficiency of this cell estimated at 21.43%, we changed the reflective gold layer with different other reflective layers such as (Al, Cr, Be, Ni, Ti…) in order to increase the efficiency of this solar cell and reduce the cost because the cost of gold is high, we found that the efficiency increased in most of the candidates to reach 24.23% when Be was placed as a reflective layer, and this is a significant increase in the efficiency of the solar cell.

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Maroua chahmi , Mounir BOURAS , Moufdi Hadjab , ,(2022), Improve Efficiency and Reduce Cost of Perovskite-Based Solar Cell,ICATEEE 2022,University Mohamed Boudiaf of M’sila

This paper proposes a generalized technique to minimize power losses of PV arrays connected in Total Cross-Tied (TCT), under both current and voltage mismatch effects. The proposed method is based on the classification of the electrical data of the PV modules composing the photovoltaic array in order to identify the mismatch type, then applying an arrangement of the PV modules according to the mismatch type found. The design process of the proposed algorithm is detailed and its validity and performance are verified under different mismatch scenarios. The efficiency enhancement is verified for different mismaths cases and the computed results reveal that the proposed algorithm can achieve an improvement of around 30% in the PV array power. Furthermore, a comparative study with SuDoKu and genetic algorithms are performed. The obtained results under MATLAB/Simulink software highlighted the superiority of the proposed method in comparison to the compared ones. The enhancement resides in the implementation simplicity as well as in the minimization of the number of infection points indicating smooth I-V and P-V characteristic curves.

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Moufdi Hadjab , , (2021), A New Simplified Algorithm for Real-Time Power Optimization of TCT Interconnected PV Array under Any Mismatch Conditions, Journal Européen des Systèmes Automatisés, Vol:54, Issue:6, pages:13, International Information and Engineering Technology Association

In this study, we have investigated one of the new semiconductors oxides due to its exciting physical properties that contributes to solve many problems related to the photovoltaic (PV) industry. We have predicted the structural, electronic and optical properties of the 3R-CuGaO2 delafossite oxide based on Density Functional Theory (DFT) using the Full-Potential Linearized Augmented Plane Wave method (P-LAPW) as implemented in the Wien2k package. The recently modified semi-local Becke-Johnson potential with LDA and PBE-GGA correlation in the form of TB-mBJ was used to predict the energy band gap, linear optical dielectric function, refractive index, absorption coefficient, reflectivity, optical conductivity and the electron energy loss of 3R-CuGaO2 delafossite oxide. The gotten results show good agreement with the experimental works and theoretical data, which show that the investigated oxide is among promising material for the manufacturing of optoelectronic devices and their applications in PV field.

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Moufdi Hadjab , ,(2021), Revealing the structural and optoelectronic properties of 3R-CuGaO2 delafossite oxide: ab-initio calculations,The first National Online Conference on Materials Physics (CNLPM’22),,Attaref - Algeria

Présence en ligne

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Moufdi Hadjab , ,(2021), Présence en ligne,9th International Renewable and Sustainable Energy Conference (IRSEC’21),,Tetouan-Morocco.

In this study, we have investigated two of the new semiconductors materials due to its exciting physical properties that contributes to solve many problems related to the photovoltaic (PV) industry. We have divided this work into two parts. The first part is to study the physical properties of the XSnP2 (X= Zn and Cd) (See Figure 1) compound semiconductors in chalcopyrite phase by employing the Full Potential Linearized Augmented Plane Wave (FP-LAPW) method to solve the Kohn-Sham equations within framework of Density Functional Theory (DFT) using Wien2k tool. The atomic configuration of both cell structures are crystalized in the chalcopyrite phase. For this, the Local Density Approximation (LDA) and Wu–Cohen Generalized Gradient Approximation (WC–GGA) were employed as the exchange–correlation term to calculate the structural and electronic properties. Moreover, the Engel–Vosko GGA (EV-GGA) and the recently modified semi–local Becke–Johnson (mBJ) functional were also used to calculate the electronic and optical properties in order to get some better degree of precision. Further, ZnSnP2 and CdSnP2 solar cell devices have been modelled; device physics and performance parameters are analysed for zinc chalcogenides buffer layer, simulation results for both structures show a high efficiency.

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Moufdi Hadjab , ,(2021), Numerical Analysis of Structural, Electronic and Optical Properties of XSnP2 Semiconducting Compounds via DFT Calculations for ZCSP based thin films solar cells,The First International Conference on Renewable energy Advanced Technologies and Applications/ Research Unit for Renewable Energies in Saharan region,,Adrar, Algeria

Solar cells based on III-V semiconductor materials are widely used owing to their high efficiencies. In this work, we aim to improve the performance of the heterojunction solar cell (double junction) InGaP / GaAs. The two sub cells are interconnected by an InGaP/InGaP tunnel junction (JT) and a back surface layer (BSF) with InAlGaP and materials for the InGaP cell and the GaAs cell. The simulation is done after optimization, modeling and choice of the used materials and the thickness of different layers constituting the solar cell. The choice of materials whose gap energy is decreasing allows the absorption of the solar spectrum in its almost totality and the optimization of the thickness of layers (thin layers) allows a compromise between the performance and the cost of the design optimized structure. The InGaP/GaAs solar cell with optimal parameters is illuminated by an AM1.5 solar spectrum through an InAlGaP window layer. The extraction of current short circuit parameters (JCC), open circuit voltage (VCO), and efficiency (ɳ) are done using TcadSilvaco software.

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Moufdi Hadjab , ,(2021), A high-efficient thin films based On InGaP/GaAs tandem solar cells,The First International Conference on Renewable energy Advanced Technologies and Applications/ Research Unit for Renewable Energies in Saharan region,,Adrar, Algeria

Analysis of SEM images of polyanilines / copper particules using image processing

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Moufdi Hadjab , ,(2021), Analysis of SEM images of polyanilines / copper particules using image processing,Polymer and Mediterranean Fiber International conference’2021 (PMFIC’2021) -,Béjaia, Algérie

In this computational work, we investigate the adsorption layers of N-unsubstituted difurandiketopyrrolopyrroles (DPP). Three conformational states differing in their dipole moments are distinguished. The adsorption layers are obtained during in-silico self-assembly on graphite surface through intermolecular hydrogen bonding in all-atom MD simulations. Two experimental processes are reproduced in the modelling: the vacuum deposition of the molecules one-by-one and the construction of the adlayers using the spin-coating technique. In all simulated systems, the formation of stable supramolecular polymers is observed which build the ordered carpets on the surface. However, the binding energetics, the strength and the type of the hydrogen bonding, and diffusion of the molecules on graphite are highly sensitive to the molecular conformation. We quantify each of these characteristics and provide a molecular picture of difuran-DPP adlayers relevant for organic field-effect transistor applications.

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Moufdi Hadjab , ,(2021), Formation of difuran–diketopyrrolopyrrole adsorption layers on graphite probed in molecular simulations,American Physical Society’s March Meeting 2021, March 15-19,USA.

The main aim of this work is to determine and explain the relationships between optoelectronic properties and the sulfur anion content in Cu2ZnSn(SxSe1−x)4 solid solution. Band gap and absorption coefficient are of primary interest to the engineers and scientists researcher worked in optoelectronic field. Herein, the electronic and optical properties are calculated based on 128 conventional atoms within lattice parameters obtained at 300 K by using the FP-LAPW method combined with quasi-harmonic Debye model. The composition dependent band gaps of CZTSSe solid solutions are investigated by TB-mBJ+U. As results, all materials are semiconductors with a direct band gap ranging from 0.614 to 0.99 eV. The band gap variation increases as a function of sulfur anion content and showed a positive deviation from Vegard's law with a very small downward bowing parameter of + 0.079 eV. The density of state (DOS) calculations indicate that the energy bands of VBM involve Cu_d/anion(S/Se)_p hybridized antibonding-like states. Based on band alignment, the Ec offset between CZTS and CZTSe is larger than the Ev offset. These results are reported previously in other work and are confirmed in this study. Our work included a systematic comparison of the influence of S/(S+Se) atomic ratios on optical quantities. The dielectric function tensors show remarkable anisotropy. In addition, the static dielectric constants are found to decrease with sulfur anion content. The CZTSSe is proved to be suitable for good solar cells with high absorption coefficient (> 104 cm−1). Such deep optical studies would be helpful for future optoelectronic applications of these compounds with different S/(S+Se) atomic ratios.

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Hamza BENNACER , Moufdi Hadjab , Mohamed Issam Ziane, , (2021), Anisotropic optical properties of Cu2ZnSn(SxSe1-x)4 Solid solutions: First-principles calculations with TB-mBJ+U., Optik – Elsevier., Vol:243, Issue:, pages:167490, Elsevier

In this computational work, we investigate the adsorption layers of electrondeficient N-unsubstituted difuran-diketopyrrolopyrroles. Three conformational states differing in the mutual orientation of the central diketopyrrolopyrrole unit and furan flanks are distinguished: cis-cis, trans-trans, and cis-trans. The adsorption layers are obtained during in-silico self-assembly on graphite surface through intermolecular hydrogen bonding in all-atom MD simulations. The experimental process for the construction of the adlayers called the spincoating technique is reproduced in the modelling. In all simulated systems, the formation of stable supramolecular polymers is observed which build the ordered carpets on the surface. However, the binding energetics and the strength and the type of the hydrogen bonding are highly sensitive to the molecular conformation. We quantify each of these characteristics and provide a molecular picture of difuran-diketopyrrolopyrrole adlayers relevant for organic field-effect transistor applications.

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Moufdi Hadjab , , (2020), Adlayers of acceptor blocks based on diketopyrrolopyrrole on graphite: self-assembly and structure revealed in all-atom modelling, Herald of Tver State University. Series: Chemistry, Vol:4, Issue:46, pages:13, Herald of Tver State University - Russia

In this work, the DPP-based small molecules are investigated theoretically using Molecular Dynamics Simulations (MD). First, we calculate the geometries of diketopyrrolopyrroles (DPP) flanked with two furan rings (Fu) in trans-cis, trans-trans and cis-cis conformations. Then, we construct three model systems comprising 100 conformers on graphite surface in the simulation box of 50×50×50 nm using FORCITE module of Material Studio 9.0. After that, the MD of the adsorption monolayers is studied in NVT ensemble at room temperature. Finally, we analyze the molecular systems by calculating the concentrations profiles, the mean square displacement (MSD) as well as diffusion coefficients D for each conformer using Einstein equation.

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Moufdi Hadjab , ,(2020), Molecular Dynamics Simulation of Furan-flanked Diketopyrrolopyrroles for Organic Solar Cells Manufacturing,8th International Renewable and Sustainable Energy Conference (IRSEC’20),,Tetouan-Morocco.

The performance of copper indium gallium selenium (CIGS) based solar cells with cadmium sulfide (CdS) and magnesium zinc oxide (MgxZn1-xO) buffer layers has been investigated comparatively with the new version of a one-dimensional device simulation program for the analysis of microelectronic and photonic structures (wxAMPS-1D). The structures of solar cells have been analysed keeping in view the effect of doping as well as of thickness of buffer and absorber layers. It is observed that the conversion efficiency and external quantum efficiency (EQE) are improved using Mg0.125Zn0.875O compound buffer layer for ZnO/Mg0.125Zn0.875O/CIGS structure to 22.01% and 89.7%, respectively, whereas the obtained conversion efficiency and EQE for ZnO/CdS/CIGS structure are 21.06% and 88.78%, respectively. The obtained results are in good agreement with the recently published work and the proposed structure of solar cells would have potential regarding improvements in the existing solar cell technology.

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Hamza BENNACER , Moufdi Hadjab , , (2020), A numerical optimization study of CdS and Mg0.125Zn0.875O buffer layers in CIGS-based solar cells using wxAMPS-1D package, International Journal of Modelling and Simulation – Taylor & Francis, Vol:42, Issue:2, pages:179-191, Taylor & Francis

The physical properties of the ZnSnP2 compound semiconductors in chalcopyrite phase have been investigated by employing full potential linearized augmented plane wave (FP-LAPW) method to solve the Kohn-Sham equations within framework of Density Functional Theory (DFT) using Wien2k tool. The atomic configuration of cell structure is crystalized in the chalcopyrite phase. For this, the Local Density Approximation (LDA) and Wu–Cohen Generalized Gradient Approximation (WC–GGA) were employed as the exchange–correlation term to calculate the structural and electronic properties. Moreover, the Engel–Vosko GGA (EV-GGA) and the recently modified semi–local Becke–Johnson (mBJ) functional were also used to calculate the electronic and optical properties in order to get some better degree of precision. The obtained results are in a good agreement with the experimental data, which indicate that the studied compound is among promising material for thin films solar cells manufacturing.

Citation

Hamza BENNACER , Moufdi Hadjab , ,(2020), First-principles Prediction of Optoelectronics Properties for Zinc-Tin-Phosphate for Thin Film Solar Cells,The eighth edition of the International Renewable and Sustainable Energy Conference (IRSEC’20) (Online),Morocco

This paper is dedicated to the ab initio study of the structural and thermodynamic properties of Cu2 ZnSn(SxSe 1-x) 4 bulk alloys. The calculations are conducted using full-potential linear-augmented-plane-wave plus local-orbital (FP-LAPW + lo) method within the revised generalized gradient approximation of Perdew–Burke–Ernzerhof (GGAPBEsol). This method is used to find more valuable equilibrium structural parameters than the simplest approximations of PBE and local density approximation (LDA). The obtained struc- tural properties appear to be affected by the relaxation effect, and all alloys are thermodynamically favorable to the process according to the enthalpy of formation calculations. We find here a nonlinear dependence of lattice parameters a and c with respectively a small downward bowing parameter b of + 0.09 A ̊ and + 0.19 A ̊ for relaxed structures. The thermodynamic quantities, namely the entropy, the constant volume, the pressure heat capacity (Cv and Cp) and Debye temperature, are computed for different S/(S + Se) atomic ra- tios by varying temperature from 0 K to 1000 K. These quantities are suc- cessfully obtained by using the combined approach of FP-LAPW and a quasi- harmonic model. Overall, there is good agreement between our calculated quantities and other results.

Citation

Moufdi Hadjab , , (2019), First-Principle Computed Structural and Thermodynamic Properties of Cu2ZnSn(SxSe1-x)4 Pentanary Solid Solution, Journal of Electronic Materials, Vol:48, Issue:, pages:12, Springer

In the present work, we review the optimization of the performance of a newly defected ZnO/Si/Cu2O heterojunction solar cell using the Analysis of Microelectronic and Photonic Structures (AMPS-1D) computer simulator under the AM1.5G illumination and the operating temperature of 300 K. The light J-V characteristics were investigated by varying the input parameters and the temperature. The use of p-type Cu2O-back layer in the structure is to enhance the open-circuit voltage (VOC). The performance of ZnO/Si/Cu2O heterojunction solar cell is studied in order to optimize the layers parameters, such as the thickness of p-Si absorber layer, the doping and the defects concentrations of the p-Si absorber layer and to obtain an efficient proposed structure. The defects concentration of p-Si absorber layer was fixed in the first step at Ndef(p-Si) ¼ 1014/cm3. With the optimized p-Si layer parameters, an efficiency of 16.23% was obtained with JSC ~26.25 mA/cm2, VOC ~0.72 V and FF~0.85 for n-ZnO window (0.1 μm)/p-Si Absorber (10 μm)/p-Cu2O (0.1 μm) heterostructure. For Ndef(p-Si) lower than 1014/ cm3, the AMPS-1D simulation showed an appreciable performance. For Ndef(p-Si) ¼ 1011/cm3 we estimate best characteristics of about: JSC ~27.57 mA/cm2, VOC ~0.78 V, FF~0.90 and Eff ~ 21.78%.

Citation

Moufdi Hadjab , , (2019), Optimization of defected ZnO/Si/Cu2O heterostructure solar cell, Optical Materials, Vol:98, Issue:, pages:10, Elsevier

In the present paper, the results of a detailed computational study of the structural, electronic, optical, magnetic and thermoelectric properties of the CdXP2 (X = Si, Ge and Sn) compounds have been studied using the fullpotential linearized augmented plane wave (FP-LAPW) method. The calculated structural parameters of the title compounds are in excellent agreement with the available theoretical data. Furthermore, in order to clarify the mechanism of electronic band structure and optical transitions of CdXP2 (X = Si, Ge and Sn), the electronic structure and density of states, complex dielectric function, refractive index with extinction coefficient, optical conductivity and absorption coefficient are calculated for radiations up to 20 eV. Finally, the thermoelectric parameters are computed for 300–900 K temperature range to explore the potential of these compounds for applications in technological devices.

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Moufdi Hadjab , , (2019), Band parameters and thermoelectric properties of chalcopyrite ternary compounds CdXP2 (X =Si, Ge and Sn), Computational Condensed Matter, Vol:28, Issue:, pages:7, Elsevier

The performance of a n/p betavoltaic heterostructure, i.e. aluminum gallium arsenide (AlxGa1-xAs) on gallium arsenide (GaAs) substrate has been evaluated by nickel-63 (Ni63) beta particles irradiation with anaverage kinetic energy of 17.1 keV. The thickness of AlxGa1-xAs emitter layer was set to 1.2 μm with an aluminum molar fraction of 0.1. The thickness of GaAs base region was fixed to be 3 μm. During the calculations, the reflection from the front surface, the metallurgical interface, and the limits of the depletion region were carefully taken into account. Moreover, the equivalent circuit accounts for the ohmic losses. The simulation results reveal that by using a radioactivity density of 10 mCi/cm2, the conversion efficiency (ɳ) of an optimized device structure increases up to 33%. The other cell electrical parameters, such as the short-circuit current density (Jsc), the opencircuit voltage (Voc), and the maximum electrical power density (Pmax) are observed to be 438.09 nA/cm2, 0.97 V, and 337.35 nW/cm2, respectively.

Citation

Moufdi Hadjab , , (2019), Performance prediction of AlGaAs/GaAs betavoltaic cells irradiated by nickel-63 radioisotope, Physica B: Physics of Condensed Matter, Vol:607, Issue:, pages:9, Elsevier

Nanostructured chalcopyrite CuGaTe2 powder has been obtained by mechanical alloying process. The X-Ray diffraction analysis (XRD) has shown the powder was poly-crystalized with tetragonal structure with (112) preferential orientations. Preliminary, the first principles calculations of the physical properties have been achieved using The Density Functional Theory (DFT) [1]. The simulation have been quantified using Wien2k [2] quantum computational package by employing the Full-Potential Linearized Augmented Plane Wave (FP-LAPW) method. Structural and electronic properties of chalcopyrite semiconducting material CuGaTe2 have been investigated using LDA [3] for the exchange-correlation potential. The electronic structures and linear optical parameters have been studied using both modified semi-local Becke-Johnson potential mBJ [4]. Band structure calculations recommend that CuGaTe2 is a direct band gap semiconductor having a band gap value = 1.21 eV, Computational results are in good agreement with those acquired experimentally. The viability of powder in realization of ultra-thin-film solar cells with high performance has been proposed after simulation. The studied material exhibits capability to become a promising candidate for fabrication of optoelectronic and photovoltaic devises.

Citation

Moufdi Hadjab , ,(2019), Experimental investigation and first-principles calculations on the physical properties of CuGaTe2 for solar cells application,3ième Congrès International de physique et chimie quantique (CIPCQ’2019),Béjaia, Algérie

Introductory, the first principles calculations of the physical properties of the CIGS have been achieved using The DFT. The simulation have been quantified using Wien2k quantum computational package by employing the FP-LAPW method. Structural and electronic properties of chalcopyrite semiconducting material CIGS have been investigated using LDA for the exchange-correlation potential. The electronic structures and linear optical parameters have been studied using both modified semi-local Becke-Johnson potential mBJ. In the present work, we investigated and compared the performance of two thin film (CIGS) based solar cells, employing the wxAMPS-1D software, where the buffer layer of the cell consists of CdS. The influence of doping and thickness of both buffer and absorbent layers on the performances of the studied cell was explored, and it was found that using the CdS compound buffer layer makes it possible to obtain a conversion efficiency that exceeds 19.67% for the ZnO/CdS/CIGS structure, Our results have shown a good agreement with other recent published works.

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Moufdi Hadjab , ,(2019), First-principles calculations and numerical modeling on the structural and optoelectronics properties of chalcopyrite materials for solar cell application,The second Algerian-German international conference on new technologies and their applications,,Setif, Algeria

État de I'art technologique des cellules solai res photovoltaïques

Citation

MoufdiHadjab , ,(2019); État de I'art technologique des cellules solai res photovoltaïques,,Éditions universitaires européenes EUE

Les semiconducteurs lllV, ll-Vlet l-lll-VI2: Applications optoelectroniques

Citation

MoufdiHadjab , ,(2019); Les semiconducteurs lllV,ll-Vlet l-lll-VI2: Applications optoelectroniques,,Éditions universitaires européenes EUE